A bearing portion includes an upper dynamic pressure portion, a lower dynamic pressure portion, and an intra-bearing space defined between a lower surface of a fluid in the upper dynamic pressure portion and an upper surface of a fluid in the lower dynamic pressure portion, and not including the fluid. An airway defined in a shaft includes an inner opening arranged to be in communication with the intra-bearing space, and an outer opening arranged to be in communication with an extra-bearing space. Each of the inner and outer openings is defined in a side surface of the shaft. The extra-bearing space and the intra-bearing space are arranged to be in communication with each other through the airway. The airway is arranged to extend substantially in a straight line or lines, is angled with respect to a central axis, and has no other openings than the inner and outer openings. This contributes to preventing a gas inside of a housing from leaking out of the housing through the airway. In addition, since the airway is arranged to extend substantially in a straight line or lines to join the inner and outer openings to each other, the airway can be defined by a single process using a drill, an EDM, or the like.

A method to fabricate a fluid bearing spindle includes creating a hollow cylindrical bore through a solid workpiece. The hollow cylindrical bore has a journal bearing portion including first and second distal tapered bearing segments separated by a central bearing segment having a constant radius. Each of the first and second distal tapered bearing segments has a tapered bearing radius that increases with distance from the central bearing segment to a maximum tapered bearing radius that is in the range of 0.5 microns to 1.5 microns greater than the constant radius. Subsequently, a cylindrical spindle shaft is inserted into the hollow cylindrical bore. In an alternative embodiment, a cylindrical outer surface of the spindle shaft includes the tapered bearing segments, rather than the hollow cylindrical bore.

The invention relates to the spindle motor for driving a hard disk drive, comprising: a stationary motor component (10, 12, 16, 18), a rotary motor component (14) rotatably mounted relative to the stationary motor component using a fluid dynamic bearing system, a bearing gap (20) disposed between the stationary motor component and the rotary motor component and filled with a bearing fluid, having at least one open end, at least one sealing gap (34) for sealing the open end, at least one cover cap (30) for covering the sealing gap, which is secured to the rotatable motor component, a disk clamp (44) for attachment of at least one magnetic storage disk (48) on the rotatable motor member and an electromagnetic drive system (40, 42) to drive the rotatable motor member. The disk clamp (44, 156) is centered on a peripheral surface of the cover cap (30, 118).

Hydrodynamic bearings exploit the properties of pumping action in a fluid to support a bearing load. Conventionally, the pumping action is provided by grooved surfaces in a bearing surface of the bearing. The provision of grooves leads to functional and practical problems, though. The action of grooves on a lubrication material leads inevitably to shear stress being exerted in the fluid. This has a detrimental effect on the load performance of a hydrodynamic bearing. In practical terms, the accurate manufacture of grooves is onerous. This application discusses a way of producing a hydrodynamic bearing using a portion of a bearing surface with an interleaved pattern of materials, wherein the materials have alternate high and low (or zero) fluid slip characteristics. The varying fluid slip characteristic of the surface induces a pumping effect analogous to that provided by a grooved surface.

This bearing apparatus includes a shaft portion, a sleeve portion, and a fluid arranged between the shaft portion and the sleeve portion. A thrust dynamic pressure portion is filled with the fluid, and a surface of the fluid is defined in a seal portion. The thrust dynamic pressure portion includes a dynamic pressure generation portion including thrust dynamic pressure grooves, an intermediate portion arranged outside of the dynamic pressure generation portion and including an annular groove in the shape of a circular ring, and a discharge portion arranged outside of the annular groove and including discharge grooves. The annular groove is arranged to have a depth smaller than a minimum radial width of the seal portion. This makes it easier for any air bubble in the thrust dynamic pressure portion to travel into the seal portion in accordance with a flow of the fluid caused in the discharge portion to be discharged outward. This reduces the likelihood that any air bubble will stay in the vicinity of the dynamic pressure generation portion.

A hard disk drive according to an embodiment of the present invention includes a pivot assembly bearing device with a shaft, rolling bearings and a sleeve, a cylindrical convex portion formed in a cover member at the upper side, protruding inward, and fixed to an upper end surface of the shaft, a convex portion formed on a base member at the lower side, protruding inward, and fixed to a lower end surface of the shaft, and a labyrinth gap formed by opposing an outer peripheral surface of the convex portion to an inner peripheral surface of a sleeve in a radial direction and/or by opposing an outer peripheral surface of the convex portion to the inner peripheral surface of the sleeve in a radial direction.

A method of manufacturing a fluid bearing apparatus includes plating a metallic base material including a cylindrical base material inner circumferential surface, and pressing by bringing a contact portion of a pressing member into contact with a plating layer on the base material inner circumferential surface in the plating step. At least a portion of the pressing member including the contact portion has a Young's modulus equal to or greater than a Young's modulus of the base material. In the pressing step a surface of the plating layer is smoothened without causing a plastic deformation of the base material by bringing the pressing member into contact with the plating layer.

Provided is a sintered bearing (8) having a plurality of axial grooves (8c1) equiangularly arranged in an outer peripheral surface (8c) thereof and a plurality of dynamic pressure generating grooves (8a11) equiangularly arranged in an inner peripheral surface (8a) thereof, in which a number of the plurality of axial grooves (8c1) is an integral multiple of a number of the plurality of dynamic pressure generating grooves (8a11) on the same circumference.

A motor may include a bearing mechanism including a shaft arranged along a center axis, a sealing member has one-end closed cylindrical shape and a recess receiving a lower portion of the bearing mechanism, a stationary portion including a base defining a part of the housing, and a rotary portion rotating relative to the stationary portion about the center axis. The base has a through hole defined therein so as to have a center aligned with the center axis and pass through the base in an axial direction. The sealing member is fixed in a fixing region defined between an outer circumferential portion of the sealing member and an inner circumferential portion that defines the through hole in the base. The fixing region includes a sealing region where a clearance between the sealing member and the base is closed.

A motor may include a bearing mechanism including a shaft arranged along a center axis, a sealing member has one-end closed cylindrical shape and a recess receiving a lower portion of the bearing mechanism, a stationary portion including a base defining a part of the housing, and a rotary portion rotating relative to the stationary portion about the center axis. The base has a through hole defined therein so as to have a center aligned with the center axis and pass through the base in an axial direction. The sealing member is fixed in a fixing region defined between an outer circumferential portion of the sealing member and an inner circumferential portion that defines the through hole in the base. The fixing region includes a sealing region where a clearance between the sealing member and the base is closed.